Self-censorship, a form of media control in the united states, led to the mpaa film classification system which was enacted around

1967-1968

Explanation:

The MPAA (Motion Picture Association of America) film classification system was enacted around 1967-1968 in order to rate the suitability of a film for certain audiences. This was a response to self-censorship and to the Motion Picture Production Code, which was in place before the system was introduced. However, the rating system is voluntary, and movies can chose not to have a rating.